Outside pipe cutter



Patented Mar. 2, 1937 UNITED" STATES mirau'r OFFICE 3 Claims.

This invention relates to an outside pipe cutter particularly useful in oil wells, and adapted to be run into a well with the tool fitting over the pipe which is to be cut.

An object of my invention is to provide a novel means of urging the cuttersinto the pipe when the tool is rotated.

Another object is to provide an outside pipe cutter in which frictional means engage the pipe to be cut, the frictional engagement of this means causing a feed sleeve to engage the cutters and urge them inwardly into the pipe.

Another object is to provide a cutter of the character stated which is rugged in construction,

simple to operate, and which will not easily get out of order.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description, and

the appended claims.

In the drawing Figure 1 is a longitudinal sectional View of my tool.

Figure 2 is a transverse sectional view of the upper joint illustrating another feed means.

Figure 3 is a fragmentary transverse sectional view of the upper portion of the feed sleeve, constructed so as to cooperate with the feed means disclosed in Fig. 2.

Figure 4 is a sectional View taken on line 4-4 of Fig. '1.

Figure 5 is a sectional view taken on line 55 of Fig. 1.

Referring more particularly to the drawing, the numeral I indicates an outer shell which is of greater inside diameter than the pipe to be cut. A coupling joint 2 screws onto the upper end of the shell I so that more stands of pipe can be connected to the tool, all of which is usual and well known in the art.

A feed sleeve 3 fits closely within the outer shell and is rotatable in the shell. A plurality of spring arms 4 are mounted in the sleeve 3 and these springs all engage the outer surface of the pipe to be cut. The springs 4 engage the pipe to be cut with sufiicient force to tend to hold the sleeve 3 stationary relative to the shell I. It is to be understood that the shell I is mounted at the lower end of the drill pipe which drill pipe is rotated at the surface in order to accomplish the cutting operation. While the springs 4 tend to hold the sleeve 3 stationary relative to the shell I when they are gripping the pipe to be cut, still these springs will slide around the pipe to be cut when sufficient opposition is created to hold the sleeve 3 stationary, as will be further described.

A wedge ring 5 is mounted on the lower. end of the sleeve 3 and is coupled to the sleeve by a split swivel ring 6. The purpose of this coupling 5 between the sleeve 3 and the ring 5 is to enable the ring 5 to remain stationary even tho the sleeve 3 is rotating.

A plurality of cutter knives are pivotally mounted in slots 8 in the shell I. The cutters 8 10 are pivoted at their lower ends on pins 9, and the upper ends of these cutters are free to be swung inwardly against the pipe to be cut. The lower .edge of the ring 5 is chamfered-as shown at Ill-to engage the upper ends of the cutters 15 l and urge them inwardly against the pipe which is to be cut.

The sleeve 3 and the ring 5 are fed downwardly as the shell I rotates, thus feeding the cutters 1 into the pipe to sever said pipe. This downward 20 feeding motion may be accomplished as follows:

A spiral groove II is cut in the sleeve 3 adjacent the upper end thereof. A pin I2 is secured to 1 the shell I and projects into the groove II. It will be evident that when the sleeve 3 is held sta- 5 tionary-or, at least, is retarded in its free rotary movement by the springs l-the pin I2 will travel in the groove II, thus forcing the sleeve 3 downwardly, which movment will swing the cutters l inwardly, as previously described. The 30 groove I I may be constructed at its lowermost end like a bayonet joint so that a left hand rotation will be necessary in order to move the pin I2 into the inclined portion of the groove.

Another means of gradually pushing the sleeve 35 3 downwardly is shown in Figs. 2 and 3. The upper end of the sleeve 3 is cut on a slope, as shown at I3 and the joint 2 is provided with a. complementary cam I4 against which the slope I3 rests. Right hand rotation of the joint will 40 tend to urge the sleeve 3 downwardly for the purpose stated. The ring 5 should not rotate with the sleeve 3 for the reason that the hard cutter I would quickly out the ring away. A shoe I5 is attached to the lower end of the shell I for the 45 purpose of guiding the pipe-which is to be cut into the shell.

Having described my invention, I claim:

1. An outside casing cutter comprising a shell adapted to be attached to drill pipe, a sleeve ro- 50 tatably and slidably mounted in the shell, a plurality of springs on the inside of the sleeve adapted to engage the pipe which is; to be cut, a plurality of cutters pivotally mounted in the shell, the lower end of said sleeve engaging the cutters 55 whereby said cutters are swung inwardly when the sleeve is lowered, said sleeve having a cam slot therein and a bayonet notch extending into the cam slot, a pin projecting from said shell into the slot whereby the sleeve is pressed downwardly as the shell is rotated, said pin resting in the notch as the tool is lowered in a well.

2. An outside casing cutter comprising a shell adapted to be attached to drill pipe, a sleeve rotatably and slidably mounted in the shell, a plurality of springs on the inside of the sleeve adapted to engage the pipe which is to be cut, a plurality of cutters pivotally mounted in the shell, the lower end of said sleeve engaging the cutters whereby said cutters are swung inwardly when the sleeve is lowered, a cam surface on the sleeve, a cooperating cam surface in the shell, both of said surfaces engaging as the tool operates whereby the sleeve is urged downwardly as the shell 20 rotates, means releasably engaging the shell, said means being releasable on reverse rotation of the drill pipe.

3. An outside casing cutter comprising a shell adapted to be mounted on drill pipe, a sleeve rotatably and slidably mounted in the shell, a plurality of springs on the inside of the sleeve, said springs frictionally engaging the pipe which is to be out, said sleeve having a cam slot therein, a pin mounted on the shell and extending into the cam slot, said sleeve having a bayonet notch extending into the cam slot, said pin resting in the notch as the tool is lowered in a well, a plurality of cutters pivotally mounted in the shell below the sleeve, said cutters being pivoted at the lower ends thereof, and a wedge ring swivelly mounted on the lower end of the sleeve, said wedge ring engaging the cutters whereby they are forced inwardly at the upper end of said cutters.

OTIS J. MCCULLOUGH. 

